Field of the Invention
Exemplary embodiments of the present invention relate to a method and system for recovering carbonate from steel slag and, more particularly, to a method and system for extracting metal ions contained in steel slag to recover the extracted metal ions for carbonate.
Description of the Related Art
Slag is an essential product generated in steel smelting processes. This slag is essentially produced from gangue components of iron ore or coke in iron making processes, or from oxides obtained during oxidation and deoxidation of molten iron or molten steel or supplementary materials added for refining in steel making processes.
The generation of blast-furnace slag and steel slag as industrial by-products has increased rapidly every year in steel mills, but there is a lack of effort to use and apply the by-products compared to the amount of generation thereof. Accordingly, most of the by-products are buried or left in separate sites within business establishments, which leads to serious environmental issues.
Slag includes SiO2 and CaO as an elementary system, and Al2O3, FeO, MgO, P2O5, CaS, and the like depending on the type of refining reaction. Steel slag based on oxidation of molten iron or molten steel includes CaO—SiO2—FeO as an elementary system.
A variety of techniques have been developed to use steel slag, and Korean Patent Nos. 10-1487977 and 10-1175422 disclose a method of recovering Fe from steel slag and a method of recovering valuable metals from slag, respectively. However, these documents are related to recovering a Fe component from steel slag, and there has been no practical technique for recovering other components.
Accordingly, it is urgently necessary to develop techniques for recovering metal components extracted from steel slag.